* Enforces a byte limit to a textbox, so that UTF-8 entries are not arbitrarily truncated.
*/
$.fn.byteLimit = function( limit ) {
- return $(this).attr( 'maxLength', limit ).keypress( function( e ) {
- // first check to see if this is actually a character key
+
+ // Default to current attribute value
+ if ( limit == null ) {
+ limit = this.attr( 'maxLength' );
+
+ // If passed, update/set attribute value instead
+ } else {
+ this.attr( 'maxLength', limit );
+ }
+
+ // Nothing passed and/or empty attribute, return this for further chaining.
+ if ( limit == null ) {
+ return this;
+ }
+
+ // We've got something, go for it:
+ return this.keypress( function( e ) {
+ // First check to see if this is actually a character key
// being pressed.
// Based on key-event info from http://unixpapa.com/js/key.html
// jQuery should also normalize e.which to be consistent cross-browser,
// This basically figures out how many bytes a UTF-16 string (which is what js sees)
// will take in UTF-8 by replacing a 2 byte character with 2 *'s, etc, and counting that.
// Note, surrogate (\uD800-\uDFFF) characters are counted as 2 bytes, since there's two of them
- // and the actual character takes 4 bytes in UTF-8 (2*2=4). Might not work perfectly in edge cases
- // such as illegal sequences, but that should never happen.
+ // and the actual character takes 4 bytes in UTF-8 (2*2=4). Might not work perfectly in
+ // edge cases such as illegal sequences, but that should never happen.
- var len = this.value.replace( /[\u0080-\u07FF\uD800-\uDFFF]/g, '**' ).replace( /[\u0800-\uD7FF\uE000-\uFFFF]/g, '***' ).length;
- // limit-3 as this doesn't count character about to be inserted.
+ var len = this.value
+ .replace( /[\u0080-\u07FF\uD800-\uDFFF]/g, '**' )
+ .replace( /[\u0800-\uD7FF\uE000-\uFFFF]/g, '***' )
+ .length;
+
+ // limit-3 as this doesn't count the character about to be inserted.
if ( len > ( limit-3 ) ) {
e.preventDefault();
}